CB, what I said that resorts *want* guests to be as much out as possible is based on several conversations I have had with representatives of big foreign tour operators, as well as with some of the hotels' management. Actually it was one hotel's commercial manager that mentioned me that they actually counted of the percentage of guest being out for lunch, and they planned around it. Also weather forecasts play a huge role, because with rainy weather people tend to stick around rooms and lobby and eat full lunch at the buffet, and while it is sunny they hang around pool and beach and eat quick lunch at a beach restaurant.
As far as commissions, while it is possible that some hotels may ask for some commission on some tours, it is not on all of them. For example, a water park gives tour operators only about a 20% discount, while truck safaris as much as 50%. An excursion sold to water park/dolphins would not be able to pay 40-50% commission , because the very rep selling the tour gets 10 to 15% commission, the rest goes to the incoming tour operator.
Also it is important to differentiate between "tour operator", "receptive operator" and "excursion operator". Tour operator is the one who sends the people out of their home country and into the hotel, and pays for the hotel. The receptive operator is the one that picks up clients at the airport, gives them local service, and sells the excursions (at the rep tables). Sometimes foreign tour operators have delegates that work along with the receptive tour operator, and it's the delegate that sells the excursions. The money is then split between TTOO and RROO.
Receptive operator MAY be excursion operator, but most likely not. RROO run excursions like Santo Domingo and Saona at the most. At Saona/Catalina they subcontract with the excursion operator, the one that has the boats. There are only handful of them. Saona is actually a multi-layered excursion, because excursion operator (from Bavaro) may actually subcontract to another excursion operator (boat owner) and the EEOO links it with transportation.
Excursion Operators (EEOO) are the ones that make and operate excursions. They usually operate on behalf of a certain receptive tour operator, or sell to many receptive tour operators (buggies, truck safaris, marinarium, etc.)
EEOO (as mentioned those that operate truck safari, buggies, ranch, zipline, fun boat, etc.) do not sell direct to the end clients (hotel guests). They sell to receptive operators for direct sales in the hotels, and to foreign tour operators for pre-sale abroad. Though not much pre-selling is done. I mentioned it here some time ago that interest in excursions were more of fellow-hotel-guest-attended-excursion-got-emotion generated than anything else.
What I want to say is that among all the layers of sales process, the % are skimmed off at each level, but I do not think hotel would get anywhere near 40% off the ticket price.